Plant monitoring and diagnosis systems utilizing an IT technique have become widespread as measures for improving a working rate of a plant. In the plant monitoring and diagnosis system, a plant apparatus constituting a plant is provided with a monitoring sensor, and pieces of information acquired by the sensor are transmitted to the monitoring and diagnosis system. The monitoring and diagnosis system detects changes in the state of the plant apparatus from changes over time in the acquired pieces of information, a temporal fluctuation in the information, and the like, to thereby monitor and diagnose the state of the plant apparatus. The operation condition of the plant and the guidance of plant maintenance are notified to a plant manager, an operator, a person in charge of maintenance, and the like on the basis of results of the monitoring, thereby supporting the stable working and operation of the plant.
In addition, the plant apparatus is also provided with a control sensor which is used to control the plant apparatus, and the like. Information acquired by the control sensor is taken up in a local control device controlling the plant apparatus and is used for control. Information acquired by the control sensor installed in the plant apparatus may include not only control information of the plant apparatus but also monitoring information which is effective at a point of view of monitoring and diagnosis of the plant apparatus.
In addition, infrastructure monitoring and diagnosis systems utilizing an IT technique have become widespread in an information communication infrastructure field using, particularly, Ethernet (registered trademark). Monitoring and diagnosis systems monitoring the soundness of the information communication infrastructure include a defect monitoring system of a communication apparatus disclosed in PTL 1 and an abnormality detection system of an information communication network disclosed in PTL 2.